[SCSI] libfc: recode incoming PRLI handling

Reduce indentation in fc_rport_recv_prli_req() using gotos.
Also add payload length checks.
Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/libfc/fc_rport.c

@@ -1442,59 +1442,39 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 	struct fc_els_spp *spp;	/* response spp */
 	unsigned int len;
 	unsigned int plen;
-	enum fc_els_rjt_reason reason = ELS_RJT_UNAB;
-	enum fc_els_rjt_explan explan = ELS_EXPL_NONE;
 	enum fc_els_spp_resp resp;
 	struct fc_seq_els_data rjt_data;
 	u32 f_ctl;
 	u32 fcp_parm;
 	u32 roles = FC_RPORT_ROLE_UNKNOWN;
-	rjt_data.fp = NULL;
 
+	rjt_data.fp = NULL;
 	fh = fc_frame_header_get(rx_fp);
 
 	FC_RPORT_DBG(rdata, "Received PRLI request while in state %s\n",
 		     fc_rport_state(rdata));
 
-	switch (rdata->rp_state) {
-	case RPORT_ST_PRLI:
-	case RPORT_ST_RTV:
-	case RPORT_ST_READY:
-	case RPORT_ST_ADISC:
-		reason = ELS_RJT_NONE;
-		break;
-	default:
-		fc_frame_free(rx_fp);
-		return;
-		break;
-	}
 	len = fr_len(rx_fp) - sizeof(*fh);
 	pp = fc_frame_payload_get(rx_fp, sizeof(*pp));
-	if (pp == NULL) {
-		reason = ELS_RJT_PROT;
-		explan = ELS_EXPL_INV_LEN;
-	} else {
+	if (!pp)
+		goto reject_len;
 	plen = ntohs(pp->prli.prli_len);
-		if ((plen % 4) != 0 || plen > len) {
-			reason = ELS_RJT_PROT;
-			explan = ELS_EXPL_INV_LEN;
-		} else if (plen < len) {
+	if ((plen % 4) != 0 || plen > len || plen < 16)
+		goto reject_len;
+	if (plen < len)
 		len = plen;
-		}
 	plen = pp->prli.prli_spp_len;
 	if ((plen % 4) != 0 || plen < sizeof(*spp) ||
-		    plen > len || len < sizeof(*pp)) {
-			reason = ELS_RJT_PROT;
-			explan = ELS_EXPL_INV_LEN;
-		}
+	    plen > len || len < sizeof(*pp) || plen < 12)
+		goto reject_len;
 	rspp = &pp->spp;
+
+	fp = fc_frame_alloc(lport, len);
+	if (!fp) {
+		rjt_data.reason = ELS_RJT_UNAB;
+		rjt_data.explan = ELS_EXPL_INSUF_RES;
+		goto reject;
 	}
-	if (reason != ELS_RJT_NONE ||
-	    (fp = fc_frame_alloc(lport, len)) == NULL) {
-		rjt_data.reason = reason;
-		rjt_data.explan = explan;
-		lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
-	} else {
 	sp = lport->tt.seq_start_next(sp);
 	WARN_ON(!sp);
 	pp = fc_frame_payload_get(fp, len);
@@ -1519,8 +1499,7 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 		spp->spp_type_ext = rspp->spp_type_ext;
 		spp->spp_flags = rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
 		resp = FC_SPP_RESP_ACK;
-			if (rspp->spp_flags & FC_SPP_RPA_VAL)
-				resp = FC_SPP_RESP_NO_PA;
+
 		switch (rspp->spp_type) {
 		case 0:	/* common to all FC-4 types */
 			break;
@@ -1535,8 +1514,7 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 				roles |= FC_RPORT_ROLE_FCP_TARGET;
 			rdata->ids.roles = roles;
 
-				spp->spp_params =
-					htonl(lport->service_params);
+			spp->spp_params = htonl(lport->service_params);
 			break;
 		default:
 			resp = FC_SPP_RESP_INVL;
@@ -1558,20 +1536,21 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
 		       FC_TYPE_ELS, f_ctl, 0);
 	lport->tt.seq_send(lport, sp, fp);
 
-		/*
-		 * Get lock and re-check state.
-		 */
 	switch (rdata->rp_state) {
 	case RPORT_ST_PRLI:
 		fc_rport_enter_ready(rdata);
 		break;
-		case RPORT_ST_READY:
-		case RPORT_ST_ADISC:
-			break;
 	default:
 		break;
 	}
-	}
+	goto drop;
+
+reject_len:
+	rjt_data.reason = ELS_RJT_PROT;
+	rjt_data.explan = ELS_EXPL_INV_LEN;
+reject:
+	lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
+drop:
 	fc_frame_free(rx_fp);
 }